466 



GENERATION. 



(as a consequence of the rupture of vesicles), 

 ova are not to be found on the injured side of 

 the uterus, but pregnancy takes place on the 

 other side. 



2d. When the vagina was divided in a like 

 manner at its upper part, although the usual 

 number of corpora lutea were found in the 

 ovaries, pregnancy did not occur. That the mere 

 wound itself locally, or its hurtful effects on 

 the constitution, did not prevent the develop- 

 ment of the ova, was proved by the experiment 

 purposely made of dividing the parts in the 

 same way and allowing them to reunite by 

 adhesion without obstruction of the tube, in 

 which case uterine pregnancy occurred nearly 

 as in the natural condition. 



3d. In another set of experiments oblite- 

 ration of the tubes was caused to take place 

 at a later period, probably when the ova had 

 descended and may be supposed to have met 

 with the seminal fluid, and in these animals 

 pregnancy occasionally but not always oc- 

 curred. 



It would appear to follow from these expe- 

 riments, that the seminal fluid does not rise in 

 the female genital passages immediately upon 

 its introduction, and not for more than a day 

 after coition, arid that those circumstances 

 which impede the rise of the seminal fluid 

 prevent fecundation. But they do not warrant 

 the conclusion that impregnation must occur 

 in the ovaries, since the vesicles may have burst, 

 their contents be discharged, and corpora lutea 

 formed without the seminal fluid having had 

 access to the ovary; a fact which is well shewn 

 by the interesting experiment performed by 

 Dr. Blundell, of producing an obliteration of 

 the upper part of the vagina in the unim- 

 pregnated rabbit, then allowing coition to take 

 place, and then finding, no pregnancy, but 

 corpora lutea in the burst vesicles of the 

 ovary. 



These experiments appear also as of im- 

 portance in shewing that neither absorption of 

 the semen by the lymphatics or bloodvessels, 

 nor the passage by any other circuitous route, 

 nor indeed any sympathetic action established 

 by sexual union between remote parts of the 

 female generative organs, can be the means of 

 producing fecundation. 



There are, no doubt, great difficulties in the 

 way of our understanding by what manner the 

 seminal fluid accomplishes the passage up- 

 wards in the genital organs of the female. 

 Thus, the small size of the Fallopian tubes at 

 once strikes us as a powerful obstacle ; but in 

 many animals, as, for example, in the Rumi- 

 nantia, there is an equally great difficulty in 

 comprehending how the seminal fluid gains the 

 uterus itself even; for in these animals the os 

 uteri forms a long and uneven passage, inter- 

 rupted by many hard cartilaginous projections, 

 and closed in general by a very viscid and tena- 

 cious mucus. But yet the seminal fluid must 

 in all probability enter the cavity of the uterus.* 



* Burdach mentions, as supporting the view that 

 the seminal fluid may be absorbed by the blood- 

 vessels or lymphatics, and being carried into the 



In conclusion, we would remark that we 

 must either suppose fecundation to be the 

 effect of the actual contact of the seminal 

 fluid with the ova in the upper part of the 

 Fallopian tube or somewhere near the ovary, 

 or we are reduced to form the opinion that the 

 action of the seminal fluid on the lower part 

 of the female genital organs may be twofold, 

 viz. first, causing the commencement of the 

 process of fecundation by a sympathetic in- 

 fluence on the upper part of the tubes, and, 

 in the second place, perfecting the change in 

 the uterus when it meets there with the ovum. 

 We feel inclined, in the present state of our 

 knowledge, to give a preference to the first of 

 these opinions. 



Nature of the fecundating process. Hypo- 

 thesis of an aura, fyc. We return now to the 

 consideration of the essential nature of the 

 change of fecundation. 



The opinion that fecundation is attributable 

 to the agency of an aura or emanation from, 

 and not to the material contact of the seminal 

 fluid, is founded chiefly upon alleged instances 

 of conception having occurred in individuals 

 (of the human species) in whom, from unnatural 

 formation or disease, no direct passage existed 

 from the vagina or external aperture to the 

 internal organs, as well as upon some of the 

 circumstances above alluded to, as shewing the 

 difficulty of such a passage both in man and 

 animals, even in the natural condition. 



No very definite idea, it may be remarked, 

 can be attached to the term " aura," for it has 

 been employed in varous acceptations by diffe- 

 rent authors ; one considering it as of the 

 nature of a gaseous or vaporific exhalation 

 from the seminal fluid, another denying it the 

 nature of a substance even of the most etherial 

 kind, and considering it more as a spiritual or 

 vital principle ; and a third regarding it as of 

 the nature of a nervous impression. These 

 discrepancies only shew us that the term aura 

 is to be taken rather as an expression for the 

 unknown agency of the seminal fluid which 

 causes fecundation, than as indicating its modus 

 operandi or the part of its substance more 

 immediately concerned in the action. Some 

 authors have, however, even referred to direct 

 experiment in favour of the agency of an aura. 

 Mondat, for example, (De la Sterilite, 4to. 

 edition, p. 17) states that he witnessed experi- 

 ments performed by Morsaqui, of Turin, with 

 this view, from which it was found that the 

 bitch could be impregnated when it was im- 

 possible, as he states, that the substance of the 

 seminal fluid could in substance pass into the 

 uterus or other parts. Recurved tubes, con- 

 taining in the closed end a quantity of the 

 dog's seminal fluid, were introduced into the 



general circulation occasion fecundation when it 

 arrives at the ovary or other parts of the internal 

 organs, Gasp. Bartholin, Perrault, Sturm, and 

 Grassmeyer. Dr. Harlan of Philadelphia, in a 

 volume of Experimental Essays recently published, 

 states that he found that the injection of semen 

 into the bloodvessels of a bitch put a stop to the 

 heat sooner than would otherwise have been the 

 case. 



